I know it's a dumb question, but when I say "I love you" to my boyfriend, I want to actually mean it so I can't say it yet. I have strong feelings for him, but how can you tell if it's love or infatuation or just liking a lot?

Put it this way, if you need to think about it then you don't love him.
It's MORE than just "strong feelings just liking a lot" and difficult to explain clearly.

It's all encompassing and enveloping.
The rest of the world doesn't matter, just the here and now..

Sometimes we can't tell until after the relationship.

I believe that you know it's love when you spend time apart, and you feel like half of you is missing.

X Dani

When you trust someone more than you trust yourself, if his or her absence makes you go mad or forces you to think about that person over and over and even in his absence you can even his or her smell than its very much sure that you are in love or otherwise its liking or infatuation :D

Wait until you feel it before saying it. You'll feel it when you stop having these types of doubts about the feeling.

It's possible that you may never feel it with this guy, in which case you will have to reconsider this relationship.

But the feeling cannot be forced upon you. It should happen naturally.